Eosinophilic granuloma complex refers to a characteristic allergic skin reaction in cats and can manifest as different types of skin lesions referred to as eosinophilic plaques, eosinophilic granumolas or indolent ulcers. Flea allergy is thought to be the most common cause. Allergic reactions to food components, which are allergens that are inhaled into the respiratory system (atopy), and allergic reactions to other insects such as mosquitoes also can result in eosinophilic skin lesions. In unusual cases, an allergic cause cannot be found and a hereditary disorder is suspected. This complex is more common in female cats.

Eosinophilic plaques usually are found on the abdomen or the inner thighs. They are raised, red lesions that may be glistening in appearance or oozing serum. Eosinophilic plaque lesions are extremely itchy and often are surrounded by broken hairs from constant licking of the area.

Eosinophilic granulomas often are found on the backs of the legs, on the roof of the mouth or on the tongue, and on the lower lip. Lesions on the back of the legs usually are raised, round, and pink or yellow in color. More than one lesion may be present and they tend to occur in a linear distribution along the leg.

Indolent ulcers, also called rodent ulcers, almost always are found on the upper lip and usually are confined to one side. The lesions most often are raised and ulcerated.

Diagnosis and Treatment Notes:

  • Eosinophilic granuloma complex is generally diagnosed with a thorough history, physical examination and skin biopsy.
  • Treatment depends on the severity of the disease, your individual pet, and your veterinarian. Pets with eosinophilic granuloma complex are treated with flea control medication, corticosteroids, antibiotics, fatty acid supplements, hormonal drugs and possibly a special diet. Discuss treatment details when your pet is diagnosed with this condition.


What to Watch for*:

  • Raised red skin lesions
  • Ulcers on the lips, tongue or inside the mouth
  • Excessive itching
  • Hair loss

*Please notify us if you notice any of the above signs or if you have any questions!